The taxonomy of Fragilaria construens var. subsalina and two morphologically related new taxa

p. 44The taxonomy of Fragilaria construens var. subsalina and two morphologically related new taxaS

Epiphytic diatoms along environmental gradients in Western European shallow lakes

European shallow lakes; epiphyton; Bacillariophyta; bioindication; eutrophication; total phosphorus Diatom-based assays have been successfully associated worldwide with the trophic status of lakes. Several studies have demonstrated a correlation between epiphytic diatoms and nutrient load in shallow lakes and wetlands. We examine the relative importance of environmental factors in explaining the structure of epiphytic diatom communities in a set of Western European shallow lakes. The effects of lake physical/chemical, morphometric and geographical variables on diatom assemblages were tested using distance-based, canonical correspondence and regression analyses. Our results show that epiphytic diatom communities respond, mainly to physical/chemical variables, overriding the effects of lake depth, size and location. The clustering of studied systems based along a total phosphorus concentration gradient concurs with previous classification of diatom taxa and nutrient state. Assessment of epiphytic diatoms provided a potential method for shallow lake classification